package poi.copypic1;

import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;

import javax.imageio.ImageIO;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class NarrowImage {
	/**
	 * @param im
	 *            原始图像
	 * @param resizeTimes
	 *            倍数,比如0.5就是缩小一半,0.98等等double类型
	 * @return 返回处理后的图像
	 */
	public BufferedImage zoomImage(String src) {

		BufferedImage result = null;

		try {
			File srcfile = new File(src);
			if (!srcfile.exists()) {
				System.out.println("文件不存在");

			}
			BufferedImage im = ImageIO.read(srcfile);

			/* 原始图像的宽度和高度 */
			int width = im.getWidth();
			int height = im.getHeight();

			// 压缩计算
			//float resizeTimes = 0.3f; /* 这个参数是要转化成的倍数,如果是1就是转化成1倍 */
			//float resizeTimes = 2.0f;
			float resizeTimes = 0.5f;
			
			/* 调整后的图片的宽度和高度 */
			int toWidth = (int) (width * resizeTimes);
			int toHeight = (int) (height * resizeTimes);

			/* 新生成结果图片 */
			result = new BufferedImage(toWidth, toHeight, BufferedImage.TYPE_INT_RGB);

			result.getGraphics().drawImage(im.getScaledInstance(toWidth, toHeight, java.awt.Image.SCALE_SMOOTH), 0, 0,
					null);

		} catch (Exception e) {
			System.out.println("创建缩略图发生异常" + e.getMessage());
		}

		return result;

	}

	public boolean writeHighQuality(BufferedImage im, String fileFullPath) {
		try {
			/* 输出到文件流 */
			FileOutputStream newimage = new FileOutputStream(fileFullPath);
			JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(newimage);
			JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(im);
			/* 压缩质量 */
			jep.setQuality(0.9f, true);
			encoder.encode(im, jep);
			/* 近JPEG编码 */
			newimage.close();
			return true;
		} catch (Exception e) {
			return false;
		}
	}

	public static void main(String[] args) {

		String inputFoler = "D:\\pic\\clock.jpg";
		/* 这儿填写你存放要缩小图片的文件夹全地址 */
		String outputFolder = "D:\\\\pic\\\\clock-4.jpg";
		/* 这儿填写你转化后的图片存放的文件夹 */

		NarrowImage narrowImage = new NarrowImage();
		narrowImage.writeHighQuality(narrowImage.zoomImage(inputFoler), outputFolder);

	}

}
